Kukudro.A

Classification

Malware

Trojan

W97M

Kukudro.A, W97M/Kukudro.A, Trojan-Dropper.MSWord.Lafool.i

Summary

Kukudro is an MS Word macro trojan dropper written in Visual Basic for Applications (VBA). The dropper has been spammed in various emails as my_Notebook.doc inside a zip archive. Once a user opens the document, it drops and runs a binary executable.

Removal

Automatic action

Based on the settings of your F-Secure security product, it will either move the file to the quarantine where it cannot spread or cause harm, or remove it.

Suspect a file is incorrectly detected (a False Positive)?

A False Positive is when a file is incorrectly detected as harmful, usually because its code or behavior resembles known harmful programs. A False Positive will usually be fixed in a subsequent database update without any action needed on your part. If you wish, you may also:

  • Check for the latest database updates

    First check if your F-Secure security program is using the latest detection database updates, then try scanning the file again.

  • Submit a sample

    After checking, if you still believe the file is incorrectly detected, you can submit a sample of it for re-analysis.

    NOTE If the file was moved to quarantine, you need to collect the file from quarantine before you can submit it.

  • Exclude a file from further scanning

    If you are certain that the file is safe and want to continue using it, you can exclude it from further scanning by the F-Secure security product.

    Note You need administrative rights to change the settings.

Find out more

Knowledge Base

Find the latest advice in our Community Knowledge Base.

User Guide

See the user guide for your product on the Help Center.

Contact Support

Chat with or call an expert for help.

Submit a sample

Submit a file or URL for further analysis.

Technical Details

When the infected Word document is opened, the macro code inside of it will be executed. It will decode a binary file from its code and drop it as 666inse_1.exe to the root of the C: drive. Then the macro will execute the dropped 666inse_1.exe file and end. The binary executable is a trojan downloader called Small.dcu.

Please note that you are using Office 2003 or later the macro will be executed only if macros have been enabled from Word's security settings. Otherwise, the trojan uses a vulnerability in MS Word 97, 2000 and XP and will run although macros are disabled. You can find more about this vulnerability here: https://www.microsoft.com/technet/security/Bulletin/MS01-034.mspx.